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https://www.readbyqxmd.com/read/28238225/direct-modeling-of-regression-effects-for-transition-probabilities-in-the-progressive-illness-death-model
#1
Leyla Azarang, Thomas Scheike, Jacobo de Uña-Álvarez
In this work, we present direct regression analysis for the transition probabilities in the possibly non-Markov progressive illness-death model. The method is based on binomial regression, where the response is the indicator of the occupancy for the given state along time. Randomly weighted score equations that are able to remove the bias due to censoring are introduced. By solving these equations, one can estimate the possibly time-varying regression coefficients, which have an immediate interpretation as covariate effects on the transition probabilities...
February 26, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28238209/a-two-phase-model-for-chronic-disease-processes-under-intermittent-inspection
#2
Ying Wu, Richard J Cook
A model is developed for chronic diseases with an indolent phase that is followed by a phase with more active disease resulting in progression and damage. The time scales for the intensity functions for the active phase are more naturally based on the time since the start of the active phase, corresponding to a semi-Markov formulation. This two-phase model enables one to fit a separate regression model for the duration of the indolent phase and intensity-based models for the more active second phase. In cohort studies for which the disease status is only known at a series of clinical assessment times, transition times are interval-censored, which means the time origin for phase II is interval-censored...
February 26, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28237906/an-extensive-analysis-of-various-texture-feature-extractors-to-detect-diabetes-mellitus-using-facial-specific-regions
#3
Ting Shu, Bob Zhang, Yuan Yan Tang
INTRODUCTION: Researchers have recently discovered that Diabetes Mellitus can be detected through non-invasive computerized method. However, the focus has been on facial block color features. In this paper, we extensively study the effects of texture features extracted from facial specific regions at detecting Diabetes Mellitus using eight texture extractors. MATERIALS AND METHODS: The eight methods are from four texture feature families: (1) statistical texture feature family: Image Gray-scale Histogram, Gray-level Co-occurance Matrix, and Local Binary Pattern, (2) structural texture feature family: Voronoi Tessellation, (3) signal processing based texture feature family: Gaussian, Steerable, and Gabor filters, and (4) model based texture feature family: Markov Random Field...
February 22, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28237866/cost-effectiveness-of-capecitabine-and-bevacizumab-maintenance-treatment-after-first-line-induction-treatment-in-metastatic-colorectal-cancer
#4
M D Franken, E M van Rooijen, A M May, H Koffijberg, H van Tinteren, L Mol, A J Ten Tije, G J Creemers, A M T van der Velden, B C Tanis, C A Uyl-de Groot, C J A Punt, M Koopman, M G H van Oijen
AIM: Capecitabine and bevacizumab (CAP-B) maintenance therapy has shown to be more effective compared with observation in metastatic colorectal cancer patients achieving stable disease or better after six cycles of first-line capecitabine, oxaliplatin, bevacizumab treatment in terms of progression-free survival. We evaluated the cost-effectiveness of CAP-B maintenance treatment. METHODS: Decision analysis with Markov modelling to evaluate the cost-effectiveness of CAP-B maintenance compared with observation was performed based on CAIRO3 study results (n = 558)...
February 23, 2017: European Journal of Cancer
https://www.readbyqxmd.com/read/28237564/cost-utility-analysis-for-bariatric-surgery-compared-with-usual-care-for-the-treatment-of-obesity-in-australia
#5
Robbie James, Ryan Ishmael Salton, Joshua Michael Byrnes, Paul Anthony Scuffham
BACKGROUND: The uptake of bariatric surgery in Australia has been hampered by the lack of funding and lack of evidence on relative value for money. OBJECTIVES: To determine the cost-effectiveness of adjustable gastric banding (AGB), Roux-En-Y gastric bypass (RYGB), and sleeve gastrectomy (SG) versus usual care (UC). SETTING: Perspective of the Australian public healthcare system. METHODS: A Markov model was constructed to simulate the costs and outcomes for 4 approaches to managing obesity...
December 26, 2016: Surgery for Obesity and related Diseases: Official Journal of the American Society for Bariatric Surgery
https://www.readbyqxmd.com/read/28237401/unraveling-biophysical-interactions-of-radiation-pneumonitis-in-non-small-cell-lung-cancer-via-bayesian-network-analysis
#6
Yi Luo, Issam El Naqa, Daniel L McShan, Dipankar Ray, Ines Lohse, Martha M Matuszak, Dawn Owen, Shruti Jolly, Theodore S Lawrence, Feng-Ming Spring Kong, Randall K Ten Haken
BACKGROUND: In non-small-cell lung cancer radiotherapy, radiation pneumonitis≥grade 2 (RP2) depends on patients' dosimetric, clinical, biological and genomic characteristics. METHODS: We developed a Bayesian network (BN) approach to explore its potential for interpreting biophysical signaling pathways influencing RP2 from a heterogeneous dataset including single nucleotide polymorphisms, micro RNAs, cytokines, clinical data, and radiation treatment plans before and during the course of radiotherapy...
February 22, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28235776/cost-effectiveness-of-a-text-message-programme-for-the-prevention-of-recurrent-cardiovascular-events
#7
Edward Burn, Son Nghiem, Stephen Jan, Julie Redfern, Anthony Rodgers, Aravinda Thiagalingam, Nicholas Graves, Clara K Chow
OBJECTIVE: To estimate the cost-effectiveness of Tobacco, Exercise and Diet Messages (TEXT ME), a text message-based intervention that provides advice, motivation, information and support to improve health-related behaviours. METHODS: A lifetime Markov model was used to estimate major vascular events (myocardial infarctions and strokes) avoided, quality-adjusted life years (QALYs) gained, costs to the health system and the incremental cost per QALY gained. The model was informed by data from a randomised controlled trial of TEXT ME, with evidence from systematic reviews and meta-analyses used to estimate the effects of changes in risk factors on the risk of major vascular events...
February 24, 2017: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/28235415/a-systematic-review-of-health-economic-models-of-opioid-agonist-therapies-in-maintenance-treatment-of-non-prescription-opioid-dependence
#8
Mersha Chetty, James J Kenworthy, Sue Langham, Andrew Walker, William C N Dunlop
BACKGROUND: Opioid dependence is a chronic condition with substantial health, economic and social costs. The study objective was to conduct a systematic review of published health-economic models of opioid agonist therapy for non-prescription opioid dependence, to review the different modelling approaches identified, and to inform future modelling studies. METHODS: Literature searches were conducted in March 2015 in eight electronic databases, supplemented by hand-searching reference lists and searches on six National Health Technology Assessment Agency websites...
February 24, 2017: Addiction Science & Clinical Practice
https://www.readbyqxmd.com/read/28231679/-use-the-markov-decision-tree-model-to-optimize-vaccination-strategies-of-hepatitis-e-among-women-aged-15-to-49
#9
Z M Chen, S B Ji, X L Shi, Y Y Zhao, X F Zhang, H Jin
Objective: To evaluate the cost-utility of different hepatitis E vaccination strategies in women aged 15 to 49. Methods: The Markov-decision tree model was constructed to evaluate the cost-utility of three hepatitis E virus vaccination strategies. Parameters of the models were estimated on the basis of published studies and experience of experts. Both methods on sensitivity and threshold analysis were used to evaluate the uncertainties of the model. Results: Compared with non-vaccination group, strategy on post-screening vaccination with rate as 100%, could save 0...
February 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28231677/-a-systematic-review-of-worldwide-natural-history-models-of-colorectal-cancer-classification-transition-rate-and-a-recommendation-for-developing-chinese-population-specific-model
#10
Z F Li, H Y Huang, J F Shi, C G Guo, S M Zou, C C Liu, Y Wang, L Wang, S L Zhu, S L Wu, M Dai
Objective: To review the worldwide studies on natural history models among colorectal cancer (CRC), and to inform building a Chinese population-specific CRC model and developing a platform for further evaluation of CRC screening and other interventions in population in China. Methods: A structured literature search process was conducted in PubMed and the target publication dates were from January 1995 to December 2014. Information about classification systems on both colorectal cancer and precancer on corresponding transition rate, were extracted and summarized...
February 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28231313/a-stochastic-hybrid-systems-based-framework-for-modeling-dependent-failure-processes
#11
Mengfei Fan, Zhiguo Zeng, Enrico Zio, Rui Kang, Ying Chen
In this paper, we develop a framework to model and analyze systems that are subject to dependent, competing degradation processes and random shocks. The degradation processes are described by stochastic differential equations, whereas transitions between the system discrete states are triggered by random shocks. The modeling is, then, based on Stochastic Hybrid Systems (SHS), whose state space is comprised of a continuous state determined by stochastic differential equations and a discrete state driven by stochastic transitions and reset maps...
2017: PloS One
https://www.readbyqxmd.com/read/28231302/bioinformatic-prediction-of-g-protein-coupled-receptor-encoding-sequences-from-the-transcriptome-of-the-foreleg-including-the-haller-s-organ-of-the-cattle-tick-rhipicephalus-australis
#12
Sergio Munoz, Felix D Guerrero, Anastasia Kellogg, Andrew M Heekin, Ming-Ying Leung
The cattle tick of Australia, Rhipicephalus australis, is a vector for microbial parasites that cause serious bovine diseases. The Haller's organ, located in the tick's forelegs, is crucial for host detection and mating. To facilitate the development of new technologies for better control of this agricultural pest, we aimed to sequence and annotate the transcriptome of the R. australis forelegs and associated tissues, including the Haller's organ. As G protein-coupled receptors (GPCRs) are an important family of eukaryotic proteins studied as pharmaceutical targets in humans, we prioritized the identification and classification of the GPCRs expressed in the foreleg tissues...
2017: PloS One
https://www.readbyqxmd.com/read/28228159/the-effect-of-interspecific-competition-on-the-temporal-dynamics-of-aedes-albopictus-and-culex-pipiens
#13
Giovanni Marini, Giorgio Guzzetta, Frederic Baldacchino, Daniele Arnoldi, Fabrizio Montarsi, Gioia Capelli, Annapaola Rizzoli, Stefano Merler, Roberto Rosà
BACKGROUND: Aedes albopictus and Culex pipiens larvae reared in the same breeding site compete for resources, with an asymmetrical outcome that disadvantages only the latter species. The impact of these interactions on the overall ecology of these two species has not yet been assessed in the natural environment. In the present study, the temporal patterns of adult female mosquitoes from both species were analysed in north-eastern Italy, and substantial temporal shifts between abundance curves of Cx...
February 23, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28227387/detecting-cell-division-of-pseudomonas-aeruginosa-bacteria-from-bright-field-microscopy-images-with-hidden-conditional-random-fields
#14
Lee-Ling S Ong, Xinghua Zhang, Binu Kundukad, Justin Dauwels, Patrick Doyle, H Harry Asada, Lee-Ling S Ong, Xinghua Zhang, Binu Kundukad, Justin Dauwels, Patrick Doyle, H Harry Asada, Binu Kundukad, Lee-Ling S Ong, Xinghua Zhang, Justin Dauwels, Patrick Doyle, H Harry Asada
An approach to automatically detect bacteria division with temporal models is presented. To understand how bacteria migrate and proliferate to form complex multicellular behaviours such as biofilms, it is desirable to track individual bacteria and detect cell division events. Unlike eukaryotic cells, prokaryotic cells such as bacteria lack distinctive features, causing bacteria division difficult to detect in a single image frame. Furthermore, bacteria may detach, migrate close to other bacteria and may orientate themselves at an angle to the horizontal plane...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227292/a-descriptive-model-of-resting-state-networks-using-markov-chains
#15
H Xie, R Pal, S Mitra, H Xie, R Pal, S Mitra, H Xie, S Mitra
Resting-state functional connectivity (RSFC) studies considering pairwise linear correlations have attracted great interests while the underlying functional network structure still remains poorly understood. To further our understanding of RSFC, this paper presents an analysis of the resting-state networks (RSNs) based on the steady-state distributions and provides a novel angle to investigate the RSFC of multiple functional nodes. This paper evaluates the consistency of two networks based on the Hellinger distance between the steady-state distributions of the inferred Markov chain models...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227257/why-should-you-model-time-when-you-use-markov-models-for-heart-sound-analysis
#16
Jorge Oliveira, Theofrastos Mantadelis, Miguel Coimbra, Jorge Oliveira, Theofrastos Mantadelis, Miguel Coimbra, Jorge Oliveira, Miguel Coimbra, Theofrastos Mantadelis
Auscultation is a widely used technique in clinical activity to diagnose heart diseases. However, heart sounds are difficult to interpret because a) of events with very short temporal onset between them (tens of milliseconds) and b) dominant frequencies that are out of the human audible spectrum. In this paper, we propose a model to segment heart sounds using a semi-hidden Markov model instead of a hidden Markov model. Our model in difference from the state-of-the-art hidden Markov models takes in account the temporal constraints that exist in heart cycles...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227168/a-novel-method-for-splice-sites-prediction-using-sequence-component-and-hidden-markov-model
#17
Elham Pashaei, Alper Yilmaz, Mustafa Ozen, Nizamettin Aydin, Elham Pashaei, Alper Yilmaz, Mustafa Ozen, Nizamettin Aydin, Nizamettin Aydin, Alper Yilmaz, Elham Pashaei, Mustafa Ozen
With increasing growth of DNA sequence data, it has become an urgent demand to develop new methods to accurately predict the genes. The performance of gene detection methods mainly depend on the efficiency of splice site prediction methods. In this paper, a novel method for detecting splice sites is proposed by using a new effective DNA encoding method and AdaBoost.M1 classifier. Our proposed DNA encoding method is based on multi-scale component (MSC) and first order Markov model (MM1). It has been applied to the HS3D dataset with repeated 10 fold cross validation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227109/probabilistic-characterization-of-sleep-architecture-home-based-study-on-healthy-volunteers
#18
Gary Garcia-Molina, Sreeram Vissapragada, Anandi Mahadevan, Robert Goodpaster, Brady Riedner, Michele Bellesi, Giulio Tononi, Gary Garcia-Molina, Sreeram Vissapragada, Anandi Mahadevan, Robert Goodpaster, Brady Riedner, Michele Bellesi, Giulio Tononi, Robert Goodpaster, Brady Riedner, Michele Bellesi, Giulio Tononi, Gary Garcia-Molina, Sreeram Vissapragada, Anandi Mahadevan
The quantification of sleep architecture has high clinical value for diagnostic purposes. While the clinical standard to assess sleep architecture is in-lab based polysomnography, higher ecological validity can be obtained with multiple sleep recordings at home. In this paper, we use a dataset composed of fifty sleep EEG recordings at home (10 per study participant for five participants) to analyze the sleep stage transition dynamics using Markov chain based modeling. The statistical analysis of the duration of continuous sleep stage bouts is also analyzed to identify the speed of transition between sleep stages...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227061/moses-a-matlab-based-open-source-stochastic-epidemic-simulator
#19
Huseyin Atakan Varol, Huseyin Atakan Varol, Huseyin Atakan Varol
This paper presents an open-source stochastic epidemic simulator. Discrete Time Markov Chain based simulator is implemented in Matlab. The simulator capable of simulating SEQIJR (susceptible, exposed, quarantined, infected, isolated and recovered) model can be reduced to simpler models by setting some of the parameters (transition probabilities) to zero. Similarly, it can be extended to more complicated models by editing the source code. It is designed to be used for testing different control algorithms to contain epidemics...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227004/automated-tracking-segmentation-and-trajectory-classification-of-pelvic-organs-on-dynamic-mri
#20
Iman Nekooeimehr, Susana Lai-Yuen, Paul Bao, Alfredo Weitzenfeld, Stuart Hart, Iman Nekooeimehr, Susana Lai-Yuen, Paul Bao, Alfredo Weitzenfeld, Stuart Hart, Paul Bao, Susana Lai-Yuen, Stuart Hart, Alfredo Weitzenfeld, Iman Nekooeimehr
Pelvic organ prolapse is a major health problem in women where pelvic floor organs (bladder, uterus, small bowel, and rectum) fall from their normal position and bulge into the vagina. Dynamic Magnetic Resonance Imaging (DMRI) is presently used to analyze the organs' movements from rest to maximum strain providing complementary support for diagnosis. However, there is currently no automated or quantitative approach to measure the movement of the pelvic organs and their correlation with the severity of prolapse...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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